Core C. External Innovative Network Description: Core C is focused closely on the functions described In the RFA. Various CEDA members are at the hubs of a number of innovative networks, including McFadden for survey econometrics;Wilmoth, for the Human Mortality Database;participants in the Carey Program Project on biodemography with researchers at the Max Planck Institute for Demographic Research and others;Mason and Lee, with National Transfer Accounts, which involves research teams in 28 different countries on 6 continents. These networks will be strengthened and supported, and other networks developed, through various kinds of Core C activities (the Specific Aims, repeated below): a) a program of visiting researchers spending from one week or up to more than a year at CEDA, thereby building or reinforcing network links, and learning or teaching approaches, methods, and theories (with travel sometimes funded through Core A);b) a series of conferences and workshops organized by CEDA members around themes related to their research on aging, drawing on researchers from elsewhere In the US and other countries, c) A program of more focused meetings of members of existing networks to address the common goals and develop common methodology and data formats, for example, d) Harmonization of data across many countries, as in HMD and NTA;e) technical assistance activities to train Third World foreign members of the NIA funded NTA project in construction and analysis of NTA data;f) Development of specialized websites (through Core D) for sharing data, software and methods, building intellectual links, disseminating research papers and findings, posting questions, and providing information about meetings, progress etc.